now i am studing in xii matriculation. help me with a time table for my board as well as my iit preparation. suggest me some tips too prepare for both the exams

Maintaining a proper schedule for every task!
Prepare the best way by appearing as many mock tests you can, and analyze the results regularly. Try solving the portion which you find difficult in the mock tests and create a strong base.

Make sure you revise every topic thoroughly and prepare well every topic by revising time and again. Also prepare separate revision plan for last minute preparation.
good luck!